System and method for delivery of regional citrate anticoagulation to extracorporeal blood circuits

Abstract

The present invention includes a comprehensive replacement fluid system and method for the delivery of regional citrate anticoagulation (RCA) to extracorporeal blood circuits, wherein the system may include an online clearance monitor (OCM) and a circuit effluent online sensor system (OSS) for the continuous determination of patient plasma content of ultrafilterable solutes.

What is claimed is: 
     
       1. A system for regional citrate anticoagulation in an extracorporeal blood circuit including an arterial blood line arranged to be connected to a vascular access for withdrawing blood from a patient and a venous blood line arranged to be connected to the vascular access for returning blood to the patient, the system comprising:
 a hemofilter in fluid communication with the arterial and venous blood lines; 
 a first pre-filter infusion line connected to the arterial blood line upstream from the hemofilter for infusing a first pre-filter infusion solution comprising a citrate anticoagulant-containing solution into blood in the arterial blood line; 
 a second pre-filter infusion line connected to the arterial blood line upstream from the hemofilter for infusing a second pre-filter infusion solution comprising a first bicarbonate-containing solution into blood in the arterial blood line; 
 a post-filter infusion line connected to the venous blood line downstream from the hemofilter for infusing a post-filter infusion solution comprising a second bicarbonate-containing solution into blood in the venous blood line, wherein at least one of the first and second bicarbonate-containing solutions has a bicarbonate concentration of about 20-60 mmol/L; 
 an additional infusion line connected to the venous blood line downstream from a connection of the post-filter infusion line for infusing an additional infusion solution comprising a calcium- and magnesium-containing solution into blood in the venous blood line; and 
 a control program for coordinating and monitoring the operation of the system, the control program programmed to monitor plasma flow online to calculate an infusion rate of the citrate anticoagulant-containing solution and the bicarbonate solutions necessary to keep a single pass fractional extraction of citrate on the hemofilter greater than or equal to 66%. 
 
     
     
       2. The system according to  claim 1 , wherein at least one of the first pre-filter infusion solution and the additional infusion solution contain dextrose. 
     
     
       3. The system according to  claim 2 , wherein dextrose is provided at a pH of about 2-2.5. 
     
     
       4. The system according to  claim 2 , wherein a source for the first pre-filter infusion solution includes one chamber containing dextrose at a pH of about 2-2.5 and another chamber containing all other solutes from the citrate anticoagulant-containing solution. 
     
     
       5. The system according to  claim 1 , wherein the first pre-filter infusion solution, the second pre-filter infusion solution, and the post-filter infusion solution are essentially free of calcium and magnesium. 
     
     
       6. The system according to  claim 1 , wherein the second pre-filter infusion line and the post-filter infusion line are connected to a single source. 
     
     
       7. The system according to  claim 6 , wherein the second pre-filter infusion solution and the post-filter infusion solution have the same bicarbonate content. 
     
     
       8. The system according to  claim 6 , wherein the second pre-filter infusion solution and the post-filter infusion solution have the same composition. 
     
     
       9. The system according to  claim 1 , wherein a bag connected to the first pre-filter infusion line and a bag connected to the additional infusion line have different total fluid volumes. 
     
     
       10. The system according to  claim 1 , further comprising a first pre-filter pump operably connected to the first pre-filter infusion line, second pre-filter pump operably connected to the second pre-filter infusion line, a post-filter pump operably connected to the post-filter infusion line, a blood pump operably connected to the arterial blood line, and an infusion pump operably connected to the additional infusion line. 
     
     
       11. The system according to  claim 1 , further comprising an effluent fluid line in fluid communication with the hemofilter for containing a filter effluent fluid, and an ultrafiltration pump operably connected to the effluent fluid line. 
     
     
       12. The system according to  claim 11 , further comprising a solute sensor operably connected to the effluent fluid line for measuring a solute concentration in the filter effluent fluid. 
     
     
       13. The system according to  claim 12 , wherein the solute sensor includes a dextrose sensor and the control program uses data from the dextrose sensor to indicate citrate removal at the hemofilter. 
     
     
       14. The system according to  claim 12 , wherein the solute sensor includes a Raman spectroscopy sensor. 
     
     
       15. The system according to  claim 14 , wherein the solute comprises at least one of free citrate, citrate complexes, free phosphate, phosphate complexes, inulin, PAH, B12 vitamin, antibiotics, and other medications. 
     
     
       16. The system according to  claim 12 , wherein the control program is operable to generate safe citrate prescriptions for the system based upon data from the solute sensor indicative of citrate removal which do not allow citrate accumulation in the patient's plasma greater than about 4 mM. 
     
     
       17. The system according to  claim 1 , further comprising a Raman spectroscopy sensor operably connected to the extracorporeal blood circuit for monitoring a solute concentration in the blood. 
     
     
       18. The system according to  claim 17 , wherein the solute comprises at least one of albumin, inulin, PAH, antibiotics and other medications, protein-bound toxins, free citrate, citrate complexes, free phosphate, and phosphate complexes. 
     
     
       19. The system according to  claim 1 , further comprising a secondary extracorporeal blood treatment device operably connected to one of the arterial blood line downstream from a connection of the first pre-filter infusion line or the venous blood line upstream from a connection of the additional infusion line. 
     
     
       20. A method for regional citrate anticoagulation in an extracorporeal blood circuit including an arterial blood line arranged to be connected to a vascular access for withdrawing blood from a patient and a venous blood line arranged to be connected to the vascular access for returning blood to the patient, the method comprising:
 providing a hemofilter in fluid communication with the arterial and venous blood lines; 
 infusing a first pre-filter infusion solution comprising a citrate anticoagulant-containing solution into blood in the arterial blood line upstream from the hemofilter; 
 infusing a second pre-filter infusion solution comprising a first bicarbonate-containing solution into blood in the arterial blood line upstream from the hemofilter; 
 infusing a post-filter infusion solution comprising a second bicarbonate-containing solution into blood in the venous blood line downstream from the hemofilter, wherein at least one of the first and second bicarbonate-containing solutions has a bicarbonate concentration of about 20-60 mmol/L; 
 infusing an additional infusion solution comprising a calcium- and magnesium-containing solution into blood in the venous blood line downstream from a connection of the post-filter infusion solution; and 
 monitoring plasma flow online to calculate an infusion rate of the citrate anticoagulant-containing solution and the bicarbonate solutions necessary to keep a single pass fractional extraction of citrate on the hemofilter greater than or equal to 66%. 
 
     
     
       21. The method according to  claim 20 , wherein at least one of the first pre-filter infusion solution and the additional infusion solution contain dextrose. 
     
     
       22. The method according to  claim 21 , wherein dextrose is provided at a pH of about 2-2.5. 
     
     
       23. The method according to  claim 20 , wherein the first pre-filter infusion solution, the second pre-filter infusion solution, and the post-filter infusion solution are essentially free of calcium and magnesium. 
     
     
       24. The method according to  claim 20 , further comprising monitoring a performance of the hemofilter in removing a solute. 
     
     
       25. The method according to  claim 20 , further comprising providing an effluent fluid line in fluid communication with the hemofilter for containing a filter effluent fluid, and an ultrafiltration pump operably connected to the effluent fluid line. 
     
     
       26. The method according to  claim 25 , further comprising sensing a solute concentration in the filter effluent fluid within the effluent fluid line. 
     
     
       27. The method according to  claim 26 , wherein sensing a solute concentration includes determining a Raman spectrum of at least one solute. 
     
     
       28. The method according to  claim 26 , wherein sensing a solute concentration includes sensing a dextrose concentration, the method further comprising using the dextrose concentration to indicate citrate removal at the hemofilter. 
     
     
       29. The method according to  claim 25 , further comprising online clearance monitoring by delivering a bolus of the first pre-filter infusion solution, wherein the first pre-filter infusion solution contains a solute, and measuring the concentration of the solute in the filter effluent fluid at least one of before, during, and after the bolus of the first pre-filter infusion solution. 
     
     
       30. The method according to  claim 20 , further comprising monitoring a solute concentration in the blood using Raman spectroscopy. 
     
     
       31. A system for regional citrate anticoagulation in an extracorporeal blood circuit including an arterial blood line arranged to be connected to a vascular access for withdrawing blood from a patient and a venous blood line arranged to be connected to the vascular access for returning blood to the patient, the system comprising:
 a hemofilter in fluid communication with the arterial and venous blood lines; 
 a first pre-filter infusion line connected to the arterial blood line upstream from the hemofilter for infusing a first pre-filter infusion solution comprising a citrate anticoagulant-containing solution into blood in the arterial blood line; 
 a second pre-filter infusion line connected to the arterial blood line upstream from the hemofilter for infusing a second pre-filter infusion solution comprising a first bicarbonate-containing solution into blood in the arterial blood line; 
 a post-filter infusion line connected to the venous blood line downstream from the hemofilter for infusing a post-filter infusion solution comprising a second bicarbonate-containing solution into blood in the venous blood line; 
 an additional infusion line connected to the venous blood line downstream from a connection of the post-filter infusion line for infusing an additional infusion solution comprising a calcium- and magnesium-containing solution into blood in the venous blood line; 
 an effluent fluid line in fluid communication with the hemofilter for containing a filter effluent fluid; 
 a dextrose sensor operably connected to the effluent fluid line for measuring dextrose concentration in the filter effluent fluid; and 
 a control program for coordinating and monitoring the operation of the system programmed to use data from the dextrose sensor to indicate citrate removal on the hemofilter. 
 
     
     
       32. A method for regional citrate anticoagulation in an extracorporeal blood circuit including an arterial blood line arranged to be connected to a vascular access for withdrawing blood from a patient and a venous blood line arranged to be connected to the vascular access for returning blood to the patient, the method comprising:
 providing a hemofilter in fluid communication with the arterial and venous blood lines; 
 infusing a first pre-filter infusion solution comprising a citrate anticoagulant-containing solution into blood in the arterial blood line upstream from the hemofilter; 
 infusing a second pre-filter infusion solution comprising a first bicarbonate-containing solution into blood in the arterial blood line upstream from the hemofilter; 
 infusing a post-filter infusion solution comprising a second bicarbonate-containing solution into blood in the venous blood line downstream from the hemofilter; 
 infusing an additional infusion solution comprising a calcium- and magnesium-containing solution into blood in the venous blood line downstream from a connection of the post-filter infusion solution; and 
 providing an effluent fluid line in fluid communication with the hemofilter for containing a filter effluent fluid; 
 sensing dextrose concentration in the filter effluent fluid; and 
 coordinating and monitoring the operation of the system by using the dextrose concentration to indicate citrate removal on the hemofilter.